扁桃果实发育过程内果皮中糖及木质素含量变化规律

Researches between Lignification of Almond Fruit Endocarp and the Activities of Related Enzyme

【目的】研究内果皮发育过程中木质素、糖含量的变化对内果皮木质化的影响,为优良扁桃品种选育奠定理论基础。【方法】以薄壳纸皮和厚壳长石头扁桃为主要试材,测定扁桃果实内果皮在整个发育时期的糖含量,分析其糖含量的变化情况;用巯基乙酸法测定内果皮木质素含量,分析其木质素沉积的进程。【结果】在扁桃果实的发育过程中,纸皮和长石头内果皮中的淀粉、可溶性糖含量均为先积累随后下降,而纸皮和长石头中还原性糖含量均呈现下降趋势,纸皮和长石头扁桃淀粉、还原性糖在花后40 d达到高峰,纸皮可溶性糖在花后40 d达到高峰,长石头可溶性糖在花后55 d达到高峰。长石头后期淀粉和还原性糖含量下降速度快于纸皮。长石头扁桃花后40 d,内果皮木质素含量开始迅速积累,纸皮扁桃花后55 d,内果皮木质素含量迅速积累。【结论】扁桃内果皮厚度与木质素、纤维素积累量呈正相关,扁桃内果皮的形成是果实内高水平糖类物质积累与代谢作为前体物质,并引起木质素的大量积累,导致内果皮木质化和加厚。

【Objective】To study the change effects of lignin and sugar content on the lignification of endocarp during the development of endocarp,so as to lay the theoretical foundation for breeding of good almond cultivars at later stage.【Method】The thin and thick shells of Zhipi and Changshitou almond were used as main material to determine sugar content of almond fruit endocarp in the whole growth period and analyze the changes of the sugar content.In addition,the lignin content of inner pericarp was determined by thioglycolic acid method,and the process of lignin deposition was analyzed.【Results】The process of the development of almond fruits,Zhipi and Changshitou in the pericarp of starch and soluble sugar contents were first accumulated and subsequently decreased;The reducing sugar content in Zhipi and Changshitou showed a downward trend,Zhipi and Changshitou almond starch,reducing sugar reached the peak at 40 d after flowering,soluble sugar of Zhipi after anthesis reached the peak at 40 d,Changshitou soluble sugar after anthesis reached the peak at 55 d.The Changshitou late starch and reducing sugar content decreased faster than that of Zhipi;The Changshitou almond 40 d after anthesis and endocarp lignin content began to accumulate rapidly and endocarp lignin content of Zhipi almond 55 d after anthesis accumulated rapidly.【Conclusion】The thickness of almond endocarp is positively correlated with the amount of lignin and cellulose accumulation.The formation of almond endocarp is the accumulation and metabolism of high levels of carbohydrate in the fruit as a precursor substance,and causes a large amount of lignin accumulation,which leads to the lignification and thickening of the endocarp.